Capacitor bank assembly

ABSTRACT

A capacitor bank includes a printed circuit board adapted for a first capacitor disposed on a first surface of the printed circuit board and a second capacitor disposed on a second, opposing surface of the printed circuit board. The first and second capacitor are connected to the printed circuit board at surface mounts pads on opposing sides of the printed circuit board that may be in electronic communication with each other. The capacitors may be connected in series or parallel. Multiple printed circuit boards with capacitors on opposing surfaces may include flexible printed circuit board portions to allow the capacitor bank to be folded into an available space.

BACKGROUND

Capacitors can be arranged in either parallel or series configurationsthat result in differing bulk characteristics to create configurationsof capacitors that achieve a voltage rating and bulk capacitance, amongother characteristic, for a desired implementation. To achieve a desiredperformance, the physical arrangement of capacitors can become quitelarge. Industries such as military avionics equipment require rugged,high-capacity capacitor configurations to provide the necessary hold-upand filtering for top-level (T/L) line replaceable units (LRU).

Traditional capacitors are constructed in a cylindrical-form whichoccupies a considerable amount of volume within the T/L, making itdifficult to efficiently package devices within the LRU. While thesecapacitors provide good capacitance values and adequate voltage ratings,their overall volume often prevents them from being installed in unitswith limited available space. Furthermore, traditional capacitorconstruction is susceptible to fatigue damage from vibrations resultingin lost or degraded performance.

Alternative capacitor technologies include ultra-dense cubes intendedfor direct placement on a printed circuit board (PCB) of a circuit cardassembly. This installation is accomplished with through-hole leads orsurface-mount soldering of the capacitors to the card. While suchconfigurations are volumetrically efficient, many circuit cards are notcompatible for mounting an array (parallel or series capacitorarrangement) of these devices.

SUMMARY

In one aspect, embodiments of the inventive concepts disclosed hereinare directed to a capacitor bank having a printed circuit board adaptedfor a first capacitor disposed on a first surface of the printed circuitboard and a second capacitor disposed on a second, opposing surface ofthe printed circuit board. The first and second capacitor are connectedto the printed circuit board at surface mounts pads on opposing sides ofthe printed circuit board. The capacitors may be connected in series orparallel.

In a further aspect, multiple printed circuit boards with capacitors onopposing surfaces may include flexible printed circuit board portions toallow the capacitor bank to be folded into an available space.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand should not restrict the scope of the claims. The accompanyingdrawings, which are incorporated in and constitute a part of thespecification, illustrate exemplary embodiments of the inventiveconcepts disclosed herein and together with the general description,serve to explain the principles.

BRIEF DESCRIPTION OF THE DRAWINGS

The numerous advantages of the embodiments of the inventive conceptsdisclosed herein may be better understood by those skilled in the art byreference to the accompanying figures in which:

FIG. 1 shows a side view of a capacitor bank according to an exemplaryembodiment;

FIG. 2 shows a side view of a capacitor bank according to an exemplaryembodiment;

FIG. 3 shows a perspective, exploded view of a capacitor bank accordingto an exemplary embodiment;

FIG. 4 shows a flowchart of a method for producing a capacitor bankaccording to an exemplary embodiment;

DETAILED DESCRIPTION

Before explaining various embodiments of the inventive conceptsdisclosed herein in detail, it is to be understood that the inventiveconcepts are not limited in their application to the arrangement of thecomponents or steps or methodologies set forth in the followingdescription or illustrated in the drawings. In the following detaileddescription of embodiments of the instant inventive concepts, numerousspecific details are set forth in order to provide a more thoroughunderstanding of the inventive concepts. However, it will be apparent toone of ordinary skill in the art having the benefit of the instantdisclosure that the inventive concepts disclosed herein may be practicedwithout these specific details. In other instances, well-known featuresmay not be described in detail to avoid unnecessarily complicating theinstant disclosure. The inventive concepts disclosed herein are capableof other embodiments or of being practiced or carried out in variousways. Also, it is to be understood that the phraseology and terminologyemployed herein is for the purpose of description and should not beregarded as limiting.

As used herein a letter following a reference numeral is intended toreference an embodiment of a feature or element that may be similar, butnot necessarily identical, to a previously described element or featurebearing the same reference numeral (e.g., 1, 1 a, 1 b). Such shorthandnotations are used for purposes of convenience only, and should not beconstrued to limit the inventive concepts disclosed herein in any wayunless expressly stated to the contrary.

Further, unless expressly stated to the contrary, “or” refers to aninclusive or and not to an exclusive or. For example, a condition A or Bis satisfied by anyone of the following: A is true (or present) and B isfalse (or not present), A is false (or not present) and B is true (orpresent), and both A and B are true (or present).

In addition, use of “a” or “an” are employed to describe elements andcomponents of embodiments of the instant inventive concepts. This isdone merely for convenience and to give a general sense of the inventiveconcepts, and “a” and “an” are intended to include one or at least oneand the singular also includes the plural unless it is obvious that itis meant otherwise.

Also, while various components may be depicted as being connecteddirectly, direct connection is not a requirement. Components may be indata communication with intervening components that are not illustratedor described.

Finally, as used herein any reference to “one embodiment,” or “someembodiments” means that a particular element, feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the inventive concepts disclosed herein.The appearances of the phrase “in at least one embodiment” in thespecification does not necessarily refer to the same embodiment.Embodiments of the inventive concepts disclosed may include one or moreof the features expressly described or inherently present herein, or anycombination or sub-combination of two or more such features.

Broadly, embodiments of the inventive concepts disclosed herein aredirected to a capacitor bank having a printed circuit board adapted fora first capacitor disposed on a first surface of the printed circuitboard and a second capacitor disposed on a second, opposing surface ofthe printed circuit board. The first and second capacitor are connectedto the printed circuit board at surface mounts pads on opposing sides ofthe printed circuit board. The capacitors may be connected in series orparallel. Multiple printed circuit boards with capacitors on opposingsurfaces may include flexible printed circuit board portions to allowthe capacitor bank to be folded into an available space.

Referring to FIG. 1 , a side view of a capacitor bank according to anexemplary embodiment is shown. The capacitor bank comprises a PCB 100and a plurality of capacitors 102, 104, 106, 108. The capacitors 102,104, 106, 108 may be surface mount capacitors affixed to the PCB 100 viacontact elements 110, 112, 114, 116, 118, 120, 122, 124 attached tocontact interfaces defined on the PCB 100. At least one contactinterface may define a pad on a top surface of the PCB 100 and a padbottom surface of the PCB 100 in electronic communication with eachother. For example, a contact interface may comprise a via through thePCB 100 or a metalized element wrapping around the PCB 100.

The capacitors 102, 104, 106, 108 are affixed to both the top surface ofthe PCB 100 and the bottom surface of the PCB 100. In at least oneembodiment, capacitors 102, 104, 106, 108 are attached to pads on theircorresponding surfaces; one or more pads on opposing surfaces may be inelectronic communication with each other. For example, a first capacitor102 is attached to pads on the top surface of the PCB 100 and a secondcapacitor 104 is attached to pads on the bottom surface of the PCB 100.The first capacitor 102 and second capacitor 104 are in electroniccommunication via at least one contact element 110 of the firstcapacitor 102 and at least one contact element 112 of the secondcapacitor 104, each attached to a pads in electronic communication. Inat least one embodiment, the first capacitor 102 and second capacitor104 may also be in electronic communication via second contact elements118, 120 of each capacitor 102, 104.

The first capacitor 102 and second capacitor 104 may be connected inseries or in parallel depending on the interconnection of thecorresponding contact elements 110, 112 and electronic paths defined onthe PCB 100. In at least one embodiment, strings of capacitors 102, 104,106, 108 may be connected via sets of pads on opposing sides of the PCB100 in electronic communication. For example, a first capacitor 102 maybe in electronic communication with a second capacitor 104 via a firstset of pads, and the second capacitor 104 may be in electroniccommunication with a third capacitor 106 via a second set of pads.

Embodiments may provide some unused PCB area due to the physicalgeometry of the capacitors 102, 104, 106, 108. In at least oneembodiment, the unused space on the PCB 100 may include elements andcircuitry pertinent to the capacitor bank, such as voltage balancingcomponents, capacitance tuning elements, resistors, transistors, and thelike.

Referring to FIG. 2 , a side view of a capacitor bank according to anexemplary embodiment is shown. The capacitor bank comprises a first PCB200 and a plurality of capacitors 202, 204, 206, 208 affixed to thefirst PCB 200 via contact elements 210, 212, 214, 216 attached to padsdefined on the first PCB 200, including pads on opposing surfaces thatmay be in electronic communication. The pads in electronic communicationput capacitors 202, 204, 206, 208 on the top surface and bottom surfacein electronic communication. Capacitors 202, 204, 206, 208 on the firstPCB 200 may be connected in series or in parallel depending on theinterconnection of the corresponding contact elements 210, 212, 214, 216and electronic paths defined on the first PCB 200. In at least oneembodiment, strings of capacitors 202, 204, 206, 208 on the first PCB200 may be connected via pads in electronic communication.

In at least one embodiment, the capacitor bank may include a second PCB218 with a plurality of capacitors 220, 224, 222, 226. The second PCB218 also defines pads in electronic communication such that thecapacitors 220, 222, 224, 226 may be in electronic communication via atleast one contact element 228, 230, 232, 234 of two or more capacitors220, 224, 222, 226 attached to both the top surface of the second PCB218 and the bottom surface of the PCB 218.

In at least one embodiment, the first PCB 200 and the second PCB 218include a flexible PCB portion 236. The flexible PCB portion 236 allowsthe first PCB 200 and the second PCB 218 to be folded into a compactconfiguration for applications where a footprint for the capacitor bankis restricted but vertical space is available on a circuit cardassembly.

Referring to FIG. 3 , a perspective, exploded view of a capacitor bankaccording to an exemplary embodiment is shown. The capacitor bank may becompact as compared to existing capacitor banks where capacitors 302,304 are attached to both the top surface of a PCB 300 and a bottomsurface of the PCB 300. The capacitors 302, 304 may be in electroniccommunication via pads 306 on opposing surfaces of the PCB 300. Thecapacitors 302, 304 and PCB 300 may be encased in a substantially sealedenclosure. In at least one embodiment, compressive thermal interfacepads 308, 310 may abut the capacitors 302, 304 to dampen vibrations andto facilitate cooling.

Referring to FIG. 4 , a flowchart of a method for producing a capacitorbank according to an exemplary embodiment is shown. During manufacture,a first capacitor is attached 400 to a first surface of a first rigidPCB portion with at least one attachment at a pad providing electronicconnectivity to both a top surface of the first rigid PCB portion and abottom surface of the first rigid PCB portion. A second capacitor isattached 402 to a second surface of the first rigid PCB portion with atleast one attachment at a corresponding pad providing electronicconnectivity to both the top surface of the first rigid PCB portion andthe bottom surface of the first rigid PCB portion. The first surface andsecond surface correspond to opposing sides of the first rigid PCBportion.

In at least one embodiment, a third capacitor is attached 404 to a firstsurface of a second rigid PCB portion at a pad providing electroniccommunication to a pad on an opposing side of the second rigid PCBportion, and a fourth capacitor is attached 406 to a second surface ofthe second rigid PCB portion at a corresponding pad. The PCB may includea flexible PCB portion connecting the first rigid PCB portion and thesecond rigid PCB portion, and the capacitor bank may be enclosed 410 inan enclosure with one or more compressive thermal interface pads.

It may be appreciated that while exemplary embodiments are describedincluding a printed circuit board with rigid and flexible portions,separate rigid printed circuit boards in electronic communication viaappropriate cables are also envisioned.

Embodiments of the present disclosure enable high density capacitorbanks in varying T/L applications, and create a single hook-up locationwhere a T/L assembly can utilize parallel or series capacitor bulkproperties. Assembling the capacitors across a single PCB provides avery compact capacitor bank that previously would require a considerableamount of physical surface area. In addition, the surface-mounting ofcapacitors to a shared PCB removes the need for tedious hand-wiring or“daisy chaining” individual capacitors across a circuit.

Embodiments of the present disclosure enable a highly modular packaging.Depending on the space available within a T/L assembly, the footprint ofthe circuit card assembly may be scaled to increase the number ofsurface-mounted capacitors. Furthermore, in applications where there isspace available, a rigid-flex-rigid PCB can be used to create aserpentine circuit card assembly with layers of capacitors.

Embodiments of the present disclosure enable remote installation of thecapacitor bank within the LRU. Whereas traditional solutions requirethat the capacitor bank be installed directly on the circuit cardassembly, the present disclosure allows the assembly to be mountedremotely within, or external to, the LRU.

It is believed that the inventive concepts disclosed herein and many oftheir attendant advantages will be understood by the foregoingdescription of embodiments of the inventive concepts, and it will beapparent that various changes may be made in the form, construction, andarrangement of the components thereof without departing from the broadscope of the inventive concepts disclosed herein or without sacrificingall of their material advantages; and individual features from variousembodiments may be combined to arrive at other embodiments. The formsherein before described being merely explanatory embodiments thereof, itis the intention of the following claims to encompass and include suchchanges. Furthermore, any of the features disclosed in relation to anyof the individual embodiments may be incorporated into any otherembodiment.

What is claimed is:
 1. A capacitor bank comprising: a printed circuitboard; and a plurality of capacitors, wherein: a first capacitor in theplurality of capacitors is disposed on a first surface of the printedcircuit board; a second capacitor in the plurality of capacitors isdisposed on a second surface of the printed circuit board opposite thefirst surface; and connection elements of the first capacitor andconnection elements of the second capacitor each utilize at least onepad on the printed circuit board in electronic communication with eachother.
 2. The capacitor bank of claim 1, wherein the first capacitor andsecond capacitor are connected in series.
 3. The capacitor bank of claim1, wherein the first capacitor and second capacitor are connected inparallel.
 4. The capacitor bank of claim 1, further comprising a voltagebalancing component disposed on the printed circuit board in electroniccommunication with the first capacitor and second capacitor.
 5. Thecapacitor bank of claim 1, wherein: the printed circuit board comprisesa first rigid portion including the first capacitor and secondcapacitor, and further comprising a second rigid portion comprising: athird capacitor in the plurality of capacitors is disposed on a firstsurface of the second printed circuit board; and a fourth capacitor inthe plurality of capacitors is disposed on a second surface of thesecond printed circuit board opposite the first surface; and connectionelements of the third capacitor and connection elements of the fourthcapacitor each utilize at least one pad on the second rigid portion inelectronic communication with each other.
 6. The capacitor bank of claim5; further comprising a flexible printed circuit board sectionconnecting the first rigid portion to the second rigid portion.
 7. Amethod of producing a capacitor bank comprising: attaching a firstcapacitor to a first surface of a printed circuit board; attaching asecond capacitor to a second surface of the printed circuit boardopposite the first surface, wherein: connection elements of the firstcapacitor and connection elements of the second capacitor each utilizeat least one pad on the printed circuit board in electroniccommunication with each other.
 8. The method of claim 7, furthercomprising aligning the first capacitor and second capacitor in series.9. The method of claim 7, further comprising aligning the firstcapacitor and second capacitor in parallel.
 10. The method of claim 7,further comprising attaching a voltage balancing component on theprinted circuit board in electronic communication with the firstcapacitor and second capacitor.
 11. The method of claim 7, furthercomprising: covering an external surface of the first capacitor with afirst compressive thermal interface pad, the external surface oppositethe printed circuit board; and covering an external surface of thesecond capacitor with a second compressive thermal interface pad, theexternal surface opposite the printed circuit board.
 12. The method ofclaim 7, further comprising: attaching a third capacitor to a firstsurface of a second printed circuit board portion; attaching a fourthcapacitor to a second surface of the second printed circuit boardportion opposite the first surface, wherein: the first capacitor andsecond capacitor are disposed on a first printed circuit board portionof the printed circuit board; and connection elements of the thirdcapacitor and connection elements of the fourth capacitor each utilizeat least one pad on the second printed circuit board portion inelectronic communication with each other.
 13. The method of claim 12,wherein the printed circuit board comprises a flexible printed circuitboard section connecting the first printed circuit board portion and thesecond printed circuit board portion.
 14. A system comprising: acapacitor bank comprising: a printed circuit board; and a plurality ofcapacitors, wherein: a first capacitor in the plurality of capacitors isdisposed on a first surface of the printed circuit board; a secondcapacitor in the plurality of capacitors is disposed on a second surfaceof the printed circuit board opposite the first surface; and connectionelements of the first capacitor and connection elements of the secondcapacitor each utilize at least one pad on the printed circuit board inelectronic communication with each other.
 15. The system of claim 14,wherein the first capacitor and second capacitor are connected inseries.
 16. The system of claim 14, wherein the first capacitor andsecond capacitor are connected in parallel.
 17. The system of claim 14,further comprising a voltage balancing component disposed on the printedcircuit board in electronic communication with the first capacitor andsecond capacitor.
 18. The system of claim 14, further comprising: afirst compressive thermal interface pad disposed proximal to an externalsurface of the first capacitor, the external surface opposite theprinted circuit board; and a second compressive thermal interface paddisposed proximal to an external surface of the second capacitor, theexternal surface opposite the printed circuit board.
 19. The system ofclaim 14, wherein the capacitor bank comprises a first capacitor bank,further comprising: a second capacitor bank comprising a printed circuitboard, a first capacitor disposed on a first surface of the printedcircuit board, and a second capacitor disposed on a second surface ofthe printed circuit board opposite the first surface, wherein connectionelements of the first capacitor and connection elements of the secondcapacitor each utilize at least pad on the printed circuit board inelectronic communication with each other.
 20. The system of claim 19,further comprising a flexible printed circuit board section connectingthe first capacitor bank to the second capacitor bank.